The use of biometric data for the identification of individuals is increasingly becoming the preferred choice in many environments due to the relative difficulty in fraudulently replicating the data. Furthermore, such an identification method requires no item of physical identification, such as an ID card, mobile phone, or payment card, to be carried.
For example, due to increasing fraud involving payment cards such as credit cards, it has been proposed to use biometric data, for example fingerprints, to identify customers in shops or supermarkets, allowing a payment transaction to be initiated. As a further example, biometric data is increasingly used for identifying individuals authorized to enter restricted areas, such as, for example, gyms, apartment blocks or vehicles, or to pass through border controls.
To identify individuals, a biometric sample is obtained and compared to the records of a database, until a match is found. In the majority of applications, speed is of the essence. For example, if a user is at the checkout of a supermarket, or at a border control gate, an identification delay of more than several seconds may be considered unacceptable. A further requirement is that there are very few errors, i.e. very few false positive and false negative results. Indeed, if a customer at the checkout of a supermarket cannot be identified, or is wrongly identified, this could lead to the customer being unable to make the payment, or to the wrong person being billed.
However, biometric databases often contain thousands or millions or records, and there is an ever present technical problem in increasing the identification speed of a person in such a database, without a significant increase in the hardware resources used to perform the identification.
Alternative solutions for identifying an individual, such as the use of a credit card or password, may lead to a relatively fast identification, but tend to be less secure than the use of biometric data. There is equally a technical problem in increasing the security of such alternative forms of identification without significantly adding to the complexity of the solution.